1. Field of the Invention
This invention relates to an electromechanical dispenser for dispensing a volatile substance, such as a piezoelectrically actuated vibratory type liquid atomization apparatus for emitting a fragrance. More particularly, it relates to such a dispenser having a single dispensing mechanism, such as a single atomization device, and a carousel that holds multiple receptacles each containing a volatile fragrant substance, the single atomization device being capable of engaging any of the receptacles by means of movement of the receptacles, such as by rotation of the carousel relative to the atomization device.
2. Description of the Related Art
Electromechanical dispensers for dispensing a volatile substance, based on a variety of operating principles or technologies, are known in the art. For example, such a dispenser may comprise a heating element for heating the volatile substance to promote vaporization and a fan or blower to generate a flow of air to direct the evaporate out of the device into the surrounding environment. Examples of dispensers of this type are described in U.S. Pat. No. 6,619,559 and U.S. Patent Application Publication Nos. 2003/0107139 and 2002/0066798. The heating element may be omitted from such a device, as shown, for example, in U.S. Pat. No. 6,713,024, or it may be replaced by an alternative means to promote evaporation, such as a diffusion screen, as described in U.S. Pat. No. 6,568,659. The fan or blower may also be omitted, as described in U.S. Pat. No. 5,805,768, according to which a heated aromatic material emanates from the dispenser into the environment upon opening of an otherwise sealed receptacle containing the material. Alternatively, U.S. Pat. No. 6,357,726 describes a variation to the fan or blower, namely, a bolus generator that delivers a pulse of air to eject a scent ring, similar to a smoke ring exhaled by a smoker. Another type of electromechanical dispenser is an ultrasonic device such as that described in U.S. Pat. No. 5,011,632, in which a fragrance solution, in the form of a thin liquid membrane formed on a vibrating surface, is vaporized by being made to absorb the energy of ultrasonic waves. Dispensers of volatile substances based on other operating principles, as well as other variations in dispensers of any given type, are known to those of ordinary skill in the art.
Regardless of the operating principle of the dispenser, it is not uncommon to include in the dispenser elements for automation and control such as a motor, a controller, and the like, to control such factors as the frequency and duration of emissions of the volatile substance, which in turn determine the intensity of the emitted fragrance. While it is of course possible to design a dispenser devoid of electrical or even mechanical components, inasmuch as many volatile substances of interest will spontaneously vaporize, in practice, such technologically primitive devices generally exhibit a variety of performance limitations, particularly with respect to the ability to vary the modes of, or otherwise control, operation of the device. U.S. Pat. Nos. 5,605,692 and 2,103,609, U.S. Patent Application Publication No. 2002/0058595, and UK Patent Application Publication GB 2 256 589 offer examples of simple devices of this sort having limited or no mechanical features.
An example of a piezoelectrically actuated vibratory type liquid atomization apparatus is described in U.S. Pat. No. 6,843,430, which is assigned to the assignee of this invention and incorporated herein by reference. As described therein, a piezoelectrically actuated vibratory type liquid atomization apparatus comprises a piezoelectric actuating element coupled to a liquid atomization plate. The piezoelectric actuating element vibrates the liquid atomization plate, in response to alternating electrical voltages applied to the actuating element. The vibration of the plate causes atomization of a liquid supplied to it by a liquid delivery system, which is arranged to deliver the liquid while the atomization plate is being vibrated. An electrical circuit is provided to supply the alternating electrical voltages to conductive elements that are arranged to be in electrical contact with opposite sides of the actuating element to apply the alternating voltages across the actuating element. The conductive elements may also serve to support the actuating element and the liquid atomization plate in a housing that contains the device.
Other examples of piezoelectric vibratory type liquid atomization apparatuses of a variety of types are described in U.S. Pat. Nos. 6,450,419, 6,085,740 and 4,301,093, and published European Patent Application EP 0 897 755.
In regard to fragrance dispensing devices, it is known that if a user is continually exposed to the same odor or fragrance, the user's olfactory sense can become desensitized to the scent. This phenomenon is referred to as “fragrance fatigue.” One way to overcome fragrance fatigue is to provide a dispenser capable of emitting different fragrances. Thus, many of the above-mentioned documents suggest a device having multiple receptacles for containing volatile substances, respectively, such that the device can hold and emit multiple, different fragrances. The different receptacles may be stationary, such as in the case of U.S. Pat. No. 6,357,726, or they may be movable, e.g., radially disposed on a tray or cartridge that may be rotated to align a given receptacle with a heater and/or an exit hole, or the like, for emission of the substance in the receptacle, such as are shown in U.S. Pat. Nos. 5,805,768, 5,605,692 and 2,103,609, U.S. Patent Application Publication Nos. 2002/0066798 and 2003/0107139, and UK Patent Application Publication GB 2 256 589. While in some cases a single dispensing mechanism (e.g., a heater and/or an exit hole) serves all of the multiple receptacles, in other cases, each of the multiple receptacles is provided with its own dispensing mechanism, in part or in whole.
Pending PCT Application No. PCT/US03/36090 (now published as International Publication No. WO 2004/043502 A1), filed Nov. 10, 2003, assigned to the assignee of this invention and incorporated herein by reference, teaches an apparatus including multiple volatile substance reservoirs, each of which is provided with its own piezoelectrically actuated atomization device. While such an apparatus is capable of providing enhanced performance, for example, in the way of a variety of modes, fragrance combinations, and control or programming, the provision of multiple atomization devices significantly increases the cost of manufacture. Thus, there remains a need for a compact piezoelectric atomization apparatus, or other type of electromechanical dispenser, capable of dispensing a variety of volatile substances with some degree of operational flexibility, that can be operated by a user in a highly convenient, simple manual fashion but that can also be provided with a degree of automation and programming control, and that can be manufactured, and hence sold, at a low cost.